Executing single file csharp files - No .csproj Required

Did you know you can execute a standalone .cs file without creating a project or solution?

With .NET 10 (C# 14), you can run C# files directly using dotnet run.

• Create a .cs file and save it. (eg: hello.cs)

 Console.WriteLine("Hello world");

• Execute the file using dotnet run ./hello.cs

• No imports necessary as by default this single file execution imports most used libraries.

• Behind the scenes the build files are stored in a temporary folder.

• This also has unix shebang (#!) support.

 #!dotnet run
 Console.WriteLine("Hello world");

• Adjust the permissions

       chmod +x hello.cs

• Execute the program with ./hello.cs

• If you also do not want the .cs extension, you can rename the filename mv hello.cs hello and it still works.

Reading command line arguments.

• Add the following contents to the .cs file.

    if (args.length > 0)
    {
      string message = string.Join(' ', args);
      Console.WriteLine(message)
    }

• You can pass the arguments as follows.

    ./hello -- This is a command line.

The -- option indicates the all following arguments to be passed to the program.

Import nuget packages

• You can also import the packages as follows.

#!dotnet run
#:package TextCopy@6.1.0

using TextCopy;

Console.WriteLine(await ClipboardService.GetTextAsync());

• When you run this program using ./clipboard.cs, it will output the contents in your clipboard.

For more info

File-Based-Programs